38.8×8.1+513×0.19+11×3.25=388×0.81+（388+125）×0.19+11×3.25=388×0.81+388×0.19+125×0.19+11×3.25=388×（0.81+0.19）+1.25×19+11×（1.25+2）=388×1+1.25×19+11×1.25+11×2=388+1.25×（19+11）+2...